This invention relates to a slider for flying a magnetic head on a fluid bearing relative to moving magnetic recording media, and in particular to a self-loading slider.
Magnetic head assemblies, comprising sliders carrying magnetic transducers, are widely and extensively used in magnetic recording apparatus, particularly disc recording apparatus. Various types of head/slider arrangements that fly on a fluid or air bearing film over the moving recording media surface are well known in the art. In order to maximize the density of stored data on such magnetic discs, the flying height of the transducer above the media is made as small as is practical, with the requirement that a substantially constant height be maintained. Conventionally, the sliders are designed such that they experience, from their support arms, a constant pressure toward the disc surface, with the lifting force of the air bearing serving to hold the slider and transducer away from the disc surface the desired amount when the disc is rotating.
Among the various types of known slider configurations are those of Garnier et al. U.S. Pat. No. 3,855,625, Roscamp et al. U.S. Pat. No. 4,081,846 and the trimaran structure of Warner U.S. Pat. No. 3,823,416.
One type of slider which has been developed and which may possess some self-loading characteristic is that shown in the Garnier et al. patent. This slider, having what is known as a taper-flat configuration with a ramped portion at the leading edge and two air bearing rails extending therefrom to the trailing edge with a rectangular recess therebetween, has provided satisfactory operation in many respects. The structure is substantially self-loading in that the rectangular recess provides a low pressure area to counteract some of the lift provided by the air bearing side rails such that the device tends to fly a distance above the moving media surface which can be controlled by the relationship between the rectangular recess and the fluid bearing rails. However, the Garnier et al. structure possesses several major disadvantages both in fabrication and in operation. Since the recessed area of that structure is rectangular and is enclosed on three sides by walls, fabrication of the device requires surface etching to produce the necessary configuration. The requirement for such etching severely restricts the types of material that can be used for manufacturing such sliders, since not all materials are susceptible of precisely controlled etching. Additionally, the sharp edges of the recessed cavity, which edges are substantially perpendicular to the air bearing surface, act as collectors of dust, debris and foreign material. A build-up of such material in this cavity can change the operating conditions of the slider and head assembly significantly.
Even the slider configurations of Roscamp et al. and Warner require expensive processes such as grinding and lapping within confined areas between side rails. Such requirements not only increase the manufacturing costs but also may have adverse effects upon the production yield.